1. Technical Field
The system of the present invention relates to oil well cuttings. More particularly, the system of the present invention relates to an apparatus and process for extracting contaminants and hydrocarbons from cuttings wastes in oil base and water base drilling fluid systems.
2. General Background
In the field of oil well drilling, during the process of drilling the well, drilling fluids are utilized for several purposes, one of which is to be pumped downhole for flushing away the cuttings as the drill bit cuts through the strata of earth. The cuttings are removed upward along the annular space between the drill string and the borehole, and are brought above ground.
In order to reuse relatively uncontaminated drilling fluid, the drilling fluid and cuttings that are brought up from the borehole are processed through a series of shale shakers and the like wherein the drilling fluid and cutting are sifted so that the drilling fluid is allowed to flow back for reuse in the borehole, and the cuttings then are removed, often times to a waste pit or the like. At present, there are pending regulations which will require that the onshore waste pits be disallowed, therefore, there is an ever impending need for a means for disposal of cuttings which are usually highly contaminated with hydrocarbons or other fluids.
There is known in the art several apparatuses, one of which pertains to a conveyor system for moving the cuttings through a chamber wherein the cuttings are "fired" by flames in order to dry them to an ashen state and thus removed as dry cuttings. The shortcoming in this particular apparatus is that an open flame near the site of a borehole is extremely dangerous and is now disallowed under present federal and state regulations. Therefore, there is a present need for an apparatus or system wherein the cuttings can be dried and safely incinerated to remove the hydrocarbons and other contaminants prior to the cuttings being hauled away and either stored or used for other purposes after decontamination.
An additional conventional method available is the cuttings washer system which is a very expensive system to utilize ranging from $300 to $600 per day plus the additional cost of an emulsifier or soap to supply the cuttings washer with dispersing capabilities. Because of recent restrictions, it becomes necessary to collect the cuttings in 25 to 50 gallon barrel tanks which must then be transported to dock site and further transported to a waste disposal site. The cost for disposal of this waste ranges from $8 to $20 a barrel thus the total costs of the washer system ranges to a $2,500 per day cost.